You didn't say where you were in NC, and, in the very very coldest regions of NC, this advice might need some modification. But, in most parts of your state, the optimal time for transplanting would be anytime between mid fall (after leaf drop) and early spring (before bud-break) as long as the ground is not frozen. See section 1 at the link below for more information. Also, you may want to check out the whole document for ideas.

Here is a link that might be useful: Planting a Tree or Shrub

"When can I transplant a crape myrtle that is eight feet tall?"

I have done this! In the early spring I was out in the cold dirt and dug one up. The bush/tree lived and honestly did not miss a beat.

The real question is "Was it worth it to transplant a crape myrtle that is eight feet tall?"

My answer after doing it is no. Unless the tree has some sort of sentimental value I would:

1-Go to the nursery/hardware store and see if I could get a new one this spring.

If yes

2 saw the old one down, apply Round up.

3 plant the new one

Moving mine just took all afternoon, some straps and my neighbors truck. Can't remember if I had the sawzall or handsaw out to cut some roots my shovel wouldn't sever.

It was really quite the project and if the new one costs less than $40 not worth it.

yes.. the old cost/benefit ratio ...

to restate tor's comment.. is 5 hours of backbreaking labor worth 40 bucks???

dig new hole... dig out plant ... 2 to 3 foot root ball .. figure out how to lift it out of the hole... drag it across the yard.. hope you estimated the new hole properly [dont want to have to lift it out of this hole] ... backfill and water the heck out of it ... fill old hole ... sit in tub for 2 hours.. wondering how you could have pain in places you forgot you had.. lol ....

all for a 15 min trip to buy the roundup and a new plant ... and a 6 pack to congratulate yourself on how it was all so easy ....

your choice... i will be impressed regardless of which route you go ....

ken

Crape Myrtle roots grow best with heat. If you transplant the tree just before it buds out in the spring, the roots will begin to grow as soon as the ground warms up. If you plant it in the fall, it will just sit in the ground with it's wounded roots all winter long, and tends to dehydrate and die.

"If you plant it in the fall, it will just sit in the ground with it's wounded roots all winter long, and tends to dehydrate and die."

That surely doesn't seem to agree with the science or my experience.

""If you plant it in the fall, it will just sit in the ground with it's wounded roots all winter long, and tends to dehydrate and die."

That surely doesn't seem to agree with the science or my experience."

I realize it sounds strange, but both the science and my experience as a Crape Myrtle farmer show that Crape Myrtles do not like to be transplanted in the cold ground; they like heat.

Gregorywoodl, there are lots of studies that show that trees and shrubs, with similar root systems to crape myrtles, do best when planted during the dormant season, including fall and winter. There are trees that are best not planted in the fall, but they are typically very different than crape myrtles. I don't have a study handy that deals specifically with crape myrtles, but maybe you do? I would be interested in seeing a scientific study that concluded that crape myrtles were best not planted in fall.

Many well respected sources specifically advise planting crape myrtles (especially for bare-root and B&B) in the fall and winter months. Clemson University (the heart of crape myrtle country), for example, states that the preferred time for planting crape myrtles is during the dormant season and that "the root system will continue to grow during the winter months." Auburn similarly advises that "balled and burlapped and bare-root (crape myrtles) are generally better able to become established if they are planted during the dormant season," and that while the canopy looses its leaves, the root system continues to stay active well into winter. Many, many other sources seem to give this same advise, especially for B&B nursery stock. I actually don't recall ever seeing the opposite advice for this group of plants. Are there reliable sources that indicate that fall planting, in proper climates of course, is ill-advised?

brandon7,
"Crape myrtles are normally planted when dormant, in the fall, late winter or early spring. In mild winter climates where the shrub is only occasionally exposed to frosts and freezing temperatures, the crape myrtle may be planted at any time that the ground can be worked. In colder climates, however, it's best to wait until spring, when the weather warms above 40 degrees Fahrenheit but before the leaves begin to bud out." Ruth de Jauregui.
http://homeguides.sfgate.com/plant-pink-velour-crepe-myrtle-68939.html
also,
"If possible plant crapemyrtle in the heat of summer when soil is warmest and root establishment is rapid", Carl Whitcomb.
http://www.lacebarkinc.com/emagpapers/crapemyrtleshowoffscreen.pdf
and,
http://www.arborday.org/shopping/trees/graphics/northern-crapemyrtle.pdf

Here is a link that might be useful: When to Plant Pink Velour Crepe Myrtle

"Crape myrtles are normally planted when dormant, in the fall, late winter or early spring..."

Exactly...I would only add that early winter would be equally fine in the OP's warmer climate.

"If possible plant crapemyrtle in the heat of summer when soil is warmest and root establishment is rapid"

Yes, when "grow(ing)...in northern areas, (and) treat(ing)...as a hardy perennial" (quoted from the introduction to the original quote), I would agree with that too.

I've never had a problem moving large ones in Spring just before they leaf out. With warm weather, they won't miss a beat.